Golf ball and method of producing the same

Abstract

The present invention provides a method of producing golf balls improved the adhesion between a ball body and a coated film on the ball body without the need of expensive and large scale facilities. The inventive method comprises the steps of: applying an adhesion enhancing agent containing a silyl component and a solvent to a surface of a ball body; drying the coated surface to form an adhesion enhancing layer having the silyl component; and applying a paint to the adhesion enhancing layer. The silyl component is capable of remaining 30 weight % or more after an elapse of one hour at a temperature of 25° C. The method is applicable to the batch operating process of manufacturing golf balls.

What is claimed is:  
     
       1. A method of producing a golf ball comprising the steps of: 
       applying an adhesion enhancing agent containing a silyl component and a solvent to a surface of a ball body;  
       drying the coated surface to form an adhesion enhancing layer having the silyl component; and  
       applying a paint to the adhesion enhancing layer; wherein the silyl component is capable of remaining 30 percent or more after an elapse of one hour at a temperature of 25° C., and wherein the silyl component includes at least 50% by weight, of a silyl component (P) with respect to a total weight of the silyl component, the silyl component (P) is represented by the following formula (1) and has a weight-average molecular weight of 300 or higher:                    
       wherein R 1  and R 2  are the same or different and each represents a saturated alkyl group having 1 to 3 carbon atoms; X and Y each represents an organic group having an amino group, an imino group or an epoxy group in a molecule; “a” and “c” are integers of 2 or 3 and “b” and “d” are integers of 0 or 1, with a proviso that a, b, c and d satisfy the following relations: a+b=3 and c+d=3; and “A” is a divalent residue containing at least one selected from an amide group, an oxy group, an imino group, a tertiary amino group and an alkylene group. 
     
     
       2. A method of producing a golf ball according to  claim 1 , wherein said silyl component (P) is produced by reacting a compound (M 1 ) represented by the following formula (2) with a compound (M 2 ) represented by the following formula (3): 
       
         
           (R 1 O) n —Si—Z 1   m   (2)  
         
       
       wherein R 1  is a saturated alkyl group having 1 to 3 carbon atoms; Z 1  is an organic group having an amino group or an imino group in a molecule; and “m” is an integer of 1 or 2 and “n” is an integer of 2 or 3, with a proviso that “m” and “n” satisfy the following relation: m+n=4; and 
       
         
           (R 2 O) q —Si—Z 2   p   (3)  
         
       
       wherein R 2  is a saturated alkyl group having 1 to 3 carbon atoms; Z 2  is an organic group having an epoxy group in a molecule; and “p” is an integer of 1 or 2 and “q” is an integer of 2 or 3, with a proviso that “p” and “q” satisfy the following relaton: p+q=4. 
     
     
       3. A method of producing a golf ball according to  claim 1 , wherein the drying is conducted so that the solvent is substantially volatilized. 
     
     
       4. A method of producing a golf ball according to  claim 1 , wherein the drying is conducted at a temperature of 20 to 50° C. for 40 to 70 minutes. 
     
     
       5. A method of producing a golf ball according to  claim 1 , wherein the ball body has the surface layer made from a resin composition containing an ionomer. 
     
     
       6. A method of producing a golf ball according to  claim 1 , wherein the ball body is made of a vulcanized rubber composition containing a diene rubber and a metal salt of an α,β-unsaturated carboxylic acid. 
     
     
       7. A golf ball comprising 
       a ball body;  
       an adhesion enhancing layer on the ball body which contains a silyl compound (P) represented by the following formula (1) and having a weight-average molecular weight of 300 or higher; and  
       a coated film coated on the adhesion enhancing layer,                    
       (wherein R 1  and R 2  are the same or different and each represents a saturated alkyl group having 1 to 3 carbon atoms; X and Y each represents an organic group having an amino group, an imino group or an epoxy group in a molecule; “a” and “c” are integers of 2 or 3 and “b” and “d” are integers of 0 or 1, with a proviso that a, b, c and d satisfy the following relations: a+b=3 and c+d=3; and “A” is a divalent residue containing at one selected from the group consisting of an amide group, an group, an imino group, a tertiary amino group and an alkylene group).